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last update : 13/06/2013
Symbol SPG26
Location 12p13.2-q14.3
HGNC id 4117
Name spastic paraplegia 26
Corresponding gene B4GALNT1
Main clinical features
  • spastic paraparesis, scissor gait, toe walking, brisk reflexes, extensor plantar responses and pes cavus PMID:15635080
  • childhood onset (between 7 and 8 years), progressive spastic paraparesis with dysarthria and distal amyotrophy in both upper and lower limbs
  • progressive dysarthria and walking difficulties, distal amyotrophy, and mild intellectual impairment PMID:15635080
  • gait difficulties occurred from 2 to 19 years of age, spasticity of the lower limbs with variable spastic of the upper limbs, increased reflexes, and bilateral Babinski sign PMID:23746551
  • Pseudobulbar dysarthria, Lower motor neuron involvement with variability at later disease stages, , decrease or absence of lower limb tendon reflexes during the course of the disease , and peripheral neuropathy predominantly of the axonal type PMID:23746551
  • Mild to moderate cognitive impairment and developmental delay, cerebellar signs and extrapyramidal signs such as facial dyskinesia and dystonia, bladder disturbances, peripherally decreased vibration sense, scoliosis, pes cavus , and strabismus PMID:23746551
  • reduced serum testosterone, hypogonadism and delayed puberty PMID:23746551
  • Genetic determination autosomal recessive
    Function/system disorder neurology
    Type disease
    Gene product
    Name beta-1,4-N-acetyl-galactosaminyl transferase 1
    Gene mutationChromosome rearrangementEffectComments
    missense     c.898C>T (p.Arg300Cys), c.1298A>C (p.Asp433Ala) PMID:23746551
    nonsense   truncated protein c.358C>T (p.Gln120*), c.682C>T (p.Arg228*) PMID:23746551
    frameshift   truncated protein c.395delC (p.Pro132Glnfs*7) PMID:23746551
    duplication     c.263dupG (p.Leu89Profs*13), c.917_922dup (p.Thr307_Val308dup) PMID:23746551
    deletion     c.1315_1317delTTC (p.Phe439del) PMID:23746551
    Remark(s) SPG26 resulting from B4GALNT1 mutations is a ganglioside biosynthesis defect and expected to lead to the accumulation of globotriaosylceramide and gangliosides G[M/D/T]3 PMID:23746551